When you look at most gum ingredient lists, you'll see a substance called gum base, which is the main component of gum and retains the flavor that carries the gum. It's also the substance that allows chewing gum to be chewed over and over again, but few companies say exactly what a "gum base" is.
The main ingredients of the base are usually synthetic rubber and polyethylene, which can also be found in plastic bags. In other words, the gum you're chewing is probably a piece of plastic.
In its early days, gum was made mainly of natural gum, extracted from sapodilla, a fruit tree in Mexico. American inventor Thomas Adams discovered it in the possession of an exiled Mexican general and accidentally invented chewing gum instead of using it to make rubber.
In waste sorting, chewing gum is classified as "other waste" and ends up in landfills. Based on the current global market, more than 374 billion pieces of gum are produced each year, equivalent to 100,000 tons of plastic. If the plastic is sorted correctly, it also means 100,000 tons of plastic will end up in landfills every year.
But according to calculations by environmental groups, only 10 per cent of gum is "properly discarded", with much of the rest turning into hard-to-remove stains on the streets.